Mobile devices such as laptops—and most recently smartphones—have included biometric devices with the purpose of user identification. The biometric devices for example include fingerprint scanners, iris scanners and camera systems capable of face and/or voice recognition. However, fingerprint identification systems suffer from the fact that users routinely leave fingerprints on various objects—and those fingerprints can be “lifted” and reproduced to circumvent fingerprint identification systems. Also, face and voice recognition systems may not be sufficiently accurate and can often be circumvented with relative ease. In this situation, iris scanning systems may be of particular interest because they are relatively more difficult to circumvent, while being very accurate and easy to use.
Various camera systems exist to capture images of the iris. In particular, there is interest in providing a biometric camera system that can be realized in a mobile device such as a smartphone or tablet. Such biometric camera systems face a number of challenges during their operation, including 1) ambient illumination (e.g. be able to operate in full sunlight); 2) motion blur (e.g. user's hand shaking while holding the smartphone and capturing iris); 3) depth of field at close distances (e.g. while taking pictures at short (“macro”) distances, the object being further or closer than the focused distance makes the image blurry); 4) additional cost and additional space for a biometric sensor; and 5) limited field of view (e.g., the camera must capture a high-resolution image of the iris for reliable identification. Since the iris is small—e.g. 12 mm in diameter—while the distance between the camera and the iris is considerable—e.g. arm's length, ˜25 cm—the camera must be considerably “zoomed in” on the face and iris area, rather than image the user and his/her surroundings as in a wide-angled shot).
Therefore, a need exists to provide a biometric camera system that is capable of addressing the above issues.